1. Field of the Invention
This invention relates to cut-off saws and more particularly to a pair of saws for making dual miter cuts on predetermined angles on each end of a truss web preparatory to joining such web with complimentary truss forming members.
It is conventional practice at the present in the building industry to employ load bearing floor and roof truss members. Each truss member is formed by overhead and lower longitudinally extending members having vertical and angularly disposed web members extending therebetween. Each angularly disposed web member is provided at its respective ends with transverse beveled surfaces, cut on predetermined angles with respect to the longitudinal axis of the web so that one miter surface flatly contacts an overhead or underlying longitudinal truss and the companion miter surface at each end of the web flatly abuts a vertical surface of the adjacent vertical truss web.
The cut-off machinery usually employed for making these beveled cuts on truss webs has comprised a singular circular saw mounted on or supported by a work table also supporting the workpiece in which the saw or the workpiece is moved to an operative position with respect to each other to form a bevel cut at a predetermined angle. A second bevel cut on the same end of a workpiece thus comprises a second setting of the saw and cutting action on the workpiece.
This procedure of making dual angular cuts on each end of a truss web can be subject to many inaccuracies, such as the length of the web and the desired angle for the respective beveled surface.
Accordingly this invention provides a pair of adjustably positioned saws which are capable of successively, in a single pass of saw movement, cutting each end of a truss web to predetermined angles.
2. Description of the Prior Art
The most pertinent patent is believe to be U.S. Pat. No. 4,098,310 which discloses apparatus for cutting a workpiece to length and bevelling the ends thereof in which a length of lumber is longitudinally guided into the machine against a stop and clamped near its lead end.
Following its clamping, the workpiece is cut to length, the stop retracted and the clamped portion moved in a lateral direction to pass its ends between two pairs of beveling saws. The clamped portion is then returned to its starting position to be unclamped and manually moved longitudinally beyond the workpiece stop for ejection from the machine.
This invention is distinctive over this and other similar patents by providing an upright frame having a horizontal work path extending through the frame in the path of a pair of angularly disposed vertically aligned and vertically reciprocated saws which bevel cuts a workpiece to truss length on predetermined angles. Following the miter cuts on one end of one truss and the adjacent end of the remaining workpiece, the finished truss is ejected laterally from the machine.